Dental floss has been in use for more than 100 years for removing plaque and entrapped food particles from between teeth, as well as providing a clean feeling in the mouth. The reduction of bacteria in the mouth is important because bacteria can cause cavities and gum disease. Dental flossing has been shown to remove bacteria in the interproximal as well as in the subgingival regions of the mouth.
The original floss consisted of twisted silk placed in a jar. Since then, many improvements have been made to dental floss to make flossing more convenient and less problematic. Most improvements have been aimed at solving the negative aspects of flossing. These include reducing fraying and breakage, providing easier insertion between teeth and providing a softer, more gum and hand friendly floss. Nylon, a high tenacity fray-resistant yarn, was first used to replace the silk, providing more fray resistance. The addition of wax to twisted multifilament yarn helped anchor fibers together, while providing a lubricious coating for easier insertion. Low friction monofilament PTFE yarn coated with wax provides good ease of insertion, depending upon the thickness and lack of twists or folds, as well as improved fray resistance. Unfortunately, PTFE monofilaments do not clean well, nor do they easily remove food particles from the space between teeth due to the low coefficient of friction of PTFE.
Further improvements to flosses were made by providing monofilament tapes made of elastomeric materials which neck down when passing into the interdental space and then expand upon relieving tension. Monofilament dental tapes made of elastomeric materials have been found to be difficult to process. One problem encountered with elastomeric dental tape products of the type described is called “telescoping.” In a roll of dental tape or bobbin of dental tape which suffers from telescoping, successive layers of the tape wound upon the core are displaced axially. Thus, the bobbin of tape takes on a generally conical shape rather than the cylindrical shape of a tape product not suffering from telescoping. A bobbin of dental tape suffering from a severe case of telescoping often cannot be mounted on or into a dispenser.
Telescoping may be the result of the elastomeric properties of the material comprising the dental tape. Bobbins of elastomeric tape formed under high tension from supply rolls are more likely to suffer telescoping since the increased tension increases the stress on the bobbin. High tension during the bobbin forming process generally stems from high tape tension during the supply roll forming process. High tension during the supply roll forming process can result from non-uniformities in the velocity or tension (i.e., accelerations and decelerations) on the tape as it is being processed or from additional tape processing such as from the coating process. During the coating process the tape is typically stretched and relaxed as it moves through coating apparatuses, thus further contributing to increased tension. Without being limited by theory, the present inventers have discovered that by lowering the tension at which the supply rolls are formed, the tension is proportionately lowered during the bobbin forming process.
There is a continuing need for coated monofilament tapes that do not have telescoping issues, as well as methods of processing these dental tapes.